Cancer News

WEDNESDAY, Dec. 22 (HealthDay News) -- The addition of pegylated interferon (peginterferon) alfa-2a to imatinib therapy in patients with chronic-phase chronic myeloid leukemia (CML) appears to result in significantly higher rates of molecular response than other treatments, according to a study published in the Dec. 23 issue of the New England Journal of Medicine.

Claude Preudhomme, M.D., Ph.D., of the Centre Hospitalier Universitaire de Lille in France, and colleagues randomized 636 patients with untreated chronic-phase CML to receive imatinib alone at a dose of 400 mg daily, imatinib (400 mg daily) plus cytarabine (20 mg per square meter of body-surface area per day on days 15 through 28 of each 28-day cycle) or peginterferon alfa-2a (90 µg weekly), or imatinib alone at a dose of 600 mg daily.

The investigators found that the rates of cytogenetic response were similar among the four groups at 12 months. The rate of a superior molecular response was 30 percent among patients who received imatinib and peginterferon alfa-2a, compared with 14 percent among patients who received 400 mg of imatinib alone. In addition, the rate of a superior molecular response was significantly higher among patients treated for more than 12 months compared with those treated for 12 months or less. While rash and depression were more frequent among patients receiving peginterferon alfa-2a, gastrointestinal events were more common among patients who received cytarabine.

"In conclusion, we found that the combination of imatinib and peginterferon alfa-2a increases the rates of molecular responses, as compared with imatinib alone, though the combination is associated with substantial toxic effects that often result in the discontinuation of peginterferon alfa-2a," the authors write. "A lower dose of peginterferon alfa-2a (e.g., 45 µg per week) might allow the combination to be given for a longer period and preserve its apparent increased antitumor efficacy."

The study was funded in part by Novartis and Roche Pharma; several authors disclosed financial relationships with these and other pharmaceutical companies.